The Meaning of Hegel's Logic
Formal logic, which was logic prior to Hegel, saw its field of study as restricted to the laws by means of which the truth of one proposition followed from that of another.
For example, in the words of John Stuart Mill:
Logic, is the science of the operations of the understanding which are subservient to the estimation of evidence: both the process itself of advancing from known truths to unknown, and all other intellectual operations in so far as auxiliary to this. It includes, therefore, the operation of Naming; .. Definition and Classification. [System of Logic, J S Mill]
Ilyenkov explains in his essay on Hegel, that Hegel's revolution in logic was effected by widening the scope of logic and the field of observation upon which the validity of logic could be tested, from logic manifested in the articulation of propositions to the manifestation of logic in all aspects of human practice.
Formal logic also put outside of its scope, the proof of primary or axiomatic truths or the derivation of the categories by which means of which propositions indicated reality. Hegel also broadened logic to include critique or derivation of these categories.
Either way, logic is concerned only with truth, that is, with thinking which corresponds to or reflects the world outside of thought, outside of individual consciousness, and further, the criterion of truth for logic is the extent to which it provides an adequate guide to practice.
Just as thought reflects the material world and can contain nothing that does not already exist in the material world, or at least the conditions for its formation, human practice is practice of material human beings in the material world, and there can be nothing in human practice which fundamentally contradicts Nature.
Thus, in elaborating the most general laws governing the development of the social practice, Hegel necessarily uncovered laws which are not unique or special to the human condition, but are objective, material laws of Nature. So, in looking not just at what thought thought of itself, but at what it did, Hegel not only and not so much discovered a far richer means of understanding individual scientific consciousness, but more importantly, the laws governing the development of collective spiritual, cultural or social activity and of the material world in general.
Hegel did not disprove or eradicate formal logic at all, he merely defined its immanent limits and uncovered its inner contradictions, its origin and its own limits, beyond which it necessarily passed over into something else, its life and its death; he negated it; he sublated it: formal logical is both overcome and maintained with dialectical logic.
Formal logic is at its most powerful, not at all when it is treated as something of little use to be violated at will, but on the contrary, when it is utilised with the maximum consistency and thoroughness, but with consciousness of its immanent limits and an understanding of when and how it supersedes itself. Nothing is more valueless than uncritical playing with logical contradiction and inconsistency justified by thoughtless and shallow reference to dialectics.
Although I think George Novack is completely wrong in his treatment of formal logic in The Logic of Marxism, his basic initial proposition on the validity of formal logic is profoundly correct:
What characteristics of material reality are reflected and conceptually reproduced in these formal laws of thought? The law of identity formulates the material fact that definite things, and traits of things, persist and maintain recognisable similarity amidst all their phenomenal changes. Wherever essential continuity exists in reality, the law of identity is applicable. ...
We could neither act nor think correctly without consciously or unconsciously obeying this law. If we couldn't recognise ourselves as the same person from moment to moment and from day to day - and there are people who cannot, who through amnesia or some other mental disturbance have lost their consciousness of self-identity - we would be lost. But the law of identity is no less valid for the rest of the universe than for human consciousness. It applies every day and everywhere to social life. If we couldn't recognise the same piece of metal through all its various operations, we couldn't get very far with production. If a farmer couldn't follow the corn he sows from the seed to the ear and then on to the meal, agriculture would be impossible. ...
The infant takes a great step forward in understanding the nature of the world when he grasps for the first time the fact that the mother who feeds him remains the same person throughout various acts of feeding. The recognition of this truth is nothing but a particular instance of the recognition of the law of identity. [The Logic of Marxism, Lecture 1, Part 4]
Thus, (continuing our theme of approaching Hegel's Logic from the point of view of a theory of cognition) perception begins when we recognise something, when we perceive something as persistent in the stream of "one damn thing after another" of immediate perception, when we can say "A = A". The whole of formal logic rests on this identity of a thing with itself, with recognition of the continuity of something. The whole of formal logic falls to pieces when "A not = A".
It is manifestly obvious that identity is an abstraction, and:
If it be the office of comparison to reduce existing differences to Identity, the science which most perfectly fulfills that end is mathematics. The reason of that is that quantitative difference is only the difference which is quite external. ... [Shorter Logic, § 117n] ... If quantity is not reached through the action of thought, but taken uncritically from our generalised image of it, we are liable to exaggerate the range of its validity, or even to raise it to the height of an absolute category. And that such a danger is real, we see when the title of exact science is restricted to those sciences the objects of which can be submitted to mathematical calculation. [Shorter Logic, § 99n]
But it is equally obvious that identity and quantity and mathematics are abstractions which reflect material reality, and identity is an abstraction which, as Novack points out, is the fundamental basis of human practice. While in a certain limited sense the world is recreated anew every minute, we act, in practice, for most of the time, on the basis first of all of continuity.
As referred to in the above quote from The Shorter Logic, the science of Identity is Mathematics. Mathematics is the science in which formal logic is applied in a specific sense, and in this special sense, is adhered to inflexibly and with unquestionable heuristic value.
In mathematics proper, it should be remembered, "A" indicates absolutely anything; it is quite meaningless (Being = Nothing) and in the proposition "A = A", the operative symbol is the "=". The proposition is an empty tautology in so far as it is deemed to make any statement about A. If we make a non-mathematical interpretation of "=", such as "this A is the same as that A" then the statement is tautological if we allow that the A refers to one and the same. If we allow that the first A is distinct from the second A, then the statement is real and valid and dialectical, but not mathematical. (But of course, if mathematics was excluded from being ultimately interpreted or applied "non-mathematically", it would be utterly lacking in content).
This is not at all to say that dialectics is absent from mathematics. Unthinkable. The movement from one proposition to another is always dialectical and only sometimes and in a certain respect formal. But without formal logic, there is no mathematics. While it is nonsense to elevate mathematics to be a model for all sciences (as was common in past centuries), it is nonsensical to devalue mathematics as a science.
But formal logic is not at all limited to mathematics. The first condition for the validity or relevance of formal logic is the relative validity of identity in respect of the precise movement of cognition in question. And Hegel had great fun of course with the struggle mathematics had with the invention of calculus. Leibnitz and Newton created this fantastically powerful instrument (which among other things is the principal method by which the laws of Nature may be expressed in general form, and which laid the basis for a new revolution in applied mathematics and natural science), only by blatantly bluffing their way over crying formal logical sleight-of-hand. It has only been in recent years that mathematics has been able to provide a formal logical derivation of calculus from its foundations. Leibnitz and Newton thought dialectically, and let posterity look after the formal proof of their discovery.
In practice we regard the world as not only subject to change, but subject to our change. In scientific thinking we regard objects critically, as subject to analysis and synthesis. To the extent that we regard an object critically, regard reality as something to be changed, then we specifically reject the law of identity, and assert that "A not = A", and formal logic takes a break. Here we cannot grasp an "A" with the aim of carrying it forward to use in other relations, but aim to revolutionise it and uncover from its clothes a new A, A-, if you like.
In the Chapter on Reflection in The Logic, Hegel deals with the Law of Identity, Law of Excluded Middle, Law of Non-Contradiction and Law of Sufficient Ground as a series of propositions or relations which unfold, each negating the other in a series of dialectical stages. These moments are discussed above in The Meaning of Reflection. For now, I would like to reflect on their status in formal logic, for while all Hegel's nineteenth century readers would have been trained in formal logic, that is probably not the case today.
The Law of Excluded Middle states that if a proposition A is not true then its denial "not-A" is true. Even within the narrow limits of formal logic this "law" is unreliable, and common sense will confirm the view that this line of reasoning is unreliable. The Dutch logician Bruuwer reconstructed mathematical logic by eliminating the law of Excluded Middle from the rule book, and showed that mathematics is little the worse for the loss. Indeed, the Quantum Logic of Weisäcker is based upon the inclusion of a truth value of "indeterminate".
The Law of Non-Contradiction states that both a proposition, A, and its denial, not-A, cannot be true within the domain of a single "theory", within the domain of validity of the law of identity, "A = A". This law is indeed fundamental to formal logic.
It is well known that the consistent application of the basic set of formal logical principles leads to "antinomies", or flat contradictions. This discovery contributed to Hegel's revolution in logic, but also led to further development within formal logic. Nowadays, the conditions which give rise to such contradictions are well known, and formal logic is able to proceed while reliably avoiding such "bad" contradictions by the introduction of a number of proscriptions on the categories.
At first glance, it would seem that an explanation of these limitations would be of great significance, but we will not pursue the question here.
In so far as the Law of Sufficient Ground may be said to exist in formal logic, it is the so-called law of decidability, that any proposition which is valid within a given theory, may be proved or disproved. In 1931, Kurt Gödel disproved this thesis in his famous Gödel's Theorem. This discovery brought about a huge crisis in the world of mathematics and logic, but it can hardly be said that it reduced formal logic to a nullity.
Nevertheless, Hegel's comment in regard to the method of proceeding from unproven axioms is very apt and is what essentially distinguishes dialectical logic from formal logic:
Formal Logic asks these sciences not to accept their subject-matter as it is immediately given; and yet herself lays down a law of thought without deducing it - in other words, without exhibiting its mediation. [Shorter Logic § 121n]
Further, the absolute status of this law is rejected in quantum mechanics, although Einstein held to his dying day that this theory could not be regarded as complete, and that therefore further grounds for the behaviour of quantum-mechanical systems were awaiting discovery. This topic is well worthy of further discussion, but will not be pursued here.
However, more significantly, complexity theory has demonstrated that phenomena in a complex system follow from the inner structure of the system which in principle cannot be derived from that inner structure by the methods of formal logic. The empirically established limitation of formal logic is more or less widely recognised outside of professional mathematicians, and is broadly the same as the commonly accepted fallaciousness of reductionism.
The other component of formal logic is the syllogism, which Hegel subjects to criticism in the Doctrine of the Notion.
The syllogism is the method of inference, first developed by formal logic, in which from two statements a third is inferred. For example, "All A are B", "C is an A", therefore "C is B".
The Universal, Particular and Individual are categories closely related to the syllogism:
All the above concepts have undergone considerable development in the history of philosophy, and the above only indicates the general scope of the concepts.
Hegel's critique of the formal logical concept of syllogism is very profound. In the first place, his understanding of the Notion (the "A" and the "B") is fundamentally at odds with that of formal logic as is his notion of Judgement (the "is"). Whereas, for formal logic, the Universal, Individual and Particular exist side-by-side and independently, in external relation to one another, for Hegel these categories are moments of development, essentially and generically connected with one another.
In the second place, his Notion of the Notion demonstrates in practice this more profound approach and provides the archetypal demonstration of his method of deriving a concept from its own immanent nature, rather than by external definition as an abstract universal.
In the third place, he anticipates the materialist critique of logic by demonstrating that the syllogism and its categories of universal, particular and individual are "forms of the notion, the vital spirit of the actual world".
The Logic of the Notion is usually treated as a science of form only, and understood to deal with the form of notion, judgement, and syllogism as form, without in the least touching the question whether anything is true. The answer to that question is supposed to depend on the content only. .... On the contrary they really are, as forms of the notion, the vital spirit of the actual world. That only is true of the actual which is true in virtue of these forms, through them and in them. As yet, however, the truth of these forms has never been considered or examined on their own account any more than their necessary interconnection. ...
The Notion as Notion contains the three following 'moments' or functional parts. (1) The first is Universality - meaning that it is in free equality with itself in its specific character. (2) The second is Particularity - that is, the specific character, in which the universal continues serenely equal to itself. (3) The third is Individuality - meaning the reflection-into-self of the specific characters of universality and particularity; which negative self-unity has complete and original determinateness, without any loss to its self-identity or universality. [Shorter Logic, § 162]
For formal logic the form of the category is considered to lie outside its domain, with a minor exception in relation to limits which are prescribed in order to avoid antinomies. The nearest formal logic can come to conceiving of the Notion is the "class", which indicates by some effective means, individuals to which can be attributed an "abstract universal". An "abstract universal" is that property which is common to many individuals.
The notion is generally associated in our minds with abstract generality, and on that account it is often described as a general conception. We speak, accordingly, of the notions of colour, plant, animal, etc. They are supposed to be arrived at by neglecting the particular features which distinguish the different colours, plants, and animals from each other, and by retaining those common to them all. ... But the universal of the notion is not a mere sum of features common to several things, confronted by a particular which enjoys an existence of its own. It is, on the contrary, self-particularising or self-specifying, and with undimmed clearness finds itself at home in its antithesis. For the sake both of cognition and of our practical conduct, it is of the utmost importance that the real universal should not be confused with what is merely held in common. ...
The universal in its true and comprehensive meaning is a thought which, as we know, cost thousands of years to make it enter into the consciousness of men. [Shorter Logic, § 163n, The Subjective Notion]
No wonder Hegel regards the logic based around the Notion as abstract universal as simply a "yawn"! It is very trivial stuff, and when not trivial usually false. When rigorously elaborated to an exceedingly high level of complexity, as in developed branches of mathematics, it can provide a substance of some interest, but is of a very restricted domain of truth, which is the same as the domain marked out by the extent of validity of the Law of Identity, and broadly recognisable as what is known in mathematics as Set Theory, the Theory of Groups, and so on.
Classes (abstract universals) in mathematics lead a kind of "double existence", once as a "collection" of "elements" having a given property and secondly as the property which constitutes the notion of the class or set. For example, "the working class" is (to the formalist) on the one hand a list of the names of employees taken from the Taxation Office records and on the other the definition "people who earn a living from a wage or salary".
Again, as an indispensable, though far from exhaustive, component of mathematics, the abstract universal has its place. But in the context of creative social or natural theory that is a very small place.
But again, the same comments as above apply. In so far as "A = A", as the relations between things remain unchanged, as the things conceived of remain separate and distinct, and things remain identical with their Notion, the notion of abstract universal retains validity. The whole of Hegel's Logic constitutes a more profound concept of "notion", and from the standpoint of Hegel's Notion, it is easy to see how limited is formal logic's notion of Abstract Universal. These aspects of formal logic are treated in Hegel's Part III of The Logic, Doctrine of the Notion.
The issue is, how to understand and recognise the boundaries of formal logic.
There is not a simple, formal answer to this question of course. Otherwise formal logic would have already discovered it!
The whole of Hegel's Logic teaches us how to determine the limits of a concept or proposition. For example, in the Doctrine of Being, we study the dialectic of Measure, which expresses the limits of Quantity and Quality. Trotsky's article The ABC of Materialist Dialectics focuses on this limitation of formal logic, that every concept has its limits of "tolerance". In the Doctrine of Essence we study, among other things, the dialectic of Form and Content. In short, Hegel, demonstrates and teaches the "art of handling concepts". As Hegel more than once complains, formal logic accepts uncritically not just the things it sees in the objective world, but the categories it uses to grasp reality.
In unfolding the limitations of formal logic from its "germ" in the law of identity - "A = A", Hegel demonstrates how all concepts must be understood, not by simple abstract universal definitions, but as dialectical, internally contradictory subject-object relations, which are nothing but moments abstracted from, or plucked out of a continually moving and developing reality. Our Notions of the world can only adequately approximate the world to the extent that our Notions reflect that essential movement and life.
For example, it is easy to say: "A is a B", "All B are C", therefore "A is C", but what is a B? "Arthur is a policeman", "Policemen work for a wage", therefore "Arthur is a worker", therefore, ...etc., etc. And you can push the definitions around as much as you like, making them "more precise", and it does take you one whit closer to an understanding of the social relations between individuals. "Worker" is an individual and a social category. Social categories have existence and laws which cannot be equated with many individual relations. The working class cannot be pulled out of the records of the Taxation Office listing all those who earnt wages in the last financial year. The whole is not equal to the sum of the parts.
This is the first limitation of formal logic, what could be called its "inner boundary". The second, its "outer boundary", is that imposed by complexity. If a system is sufficiently complex and "rich", then the phenomena that arise in it cannot be reduced to the properties of the system's component sub-systems. For example, it is fairly well-known that attempts by macro-economists to model the world economy using, for example, up to 4,000 simultaneous differential equations, invariably fails to predict any significant phenomena outside of the usual ebb and flow of indicators.
Over the past decade, a new science has emerged known as "Complexity". This science uses computer simulation to empirically investigate the outcome of very few, very simple formal rules governing the interaction of a large number of component sub-systems, or individuals, in a system.
The need for an empirical science to study these phenomena is explained by a corollary of Gödel's Theorem discovered by Alan Turing, the founder of Computer Science: that in any computational system there at least one algorithm, the results of which cannot in principle be predicted. This is a bit of truism for anyone who has programmed a complex computer system!
The implication for understanding the relation of formal and dialectical logic is profound. In any complex (i.e. real) system, the phenomena exhibited arise out of the relations of the component systems in a way which cannot in principle be deduced by formal logical analysis; and this is true even where the atomic relations are absolutely simple and static.
Such complex systems fall initially into two kinds: those where the atomic relations lead to a static or repetitive structure in the mass, where the mechanical application of formal logical analysis is valid, and those that lead to chaos, where the Law of Large Numbers and probability theory is valid. A simple measure derived from the atomic relations indicates whether the system is likely to be structured or chaotic. But there is also a third case, the border-line or transition case, where the atomic relations lead to "complex behaviour", rich in form, leaps, sudden transformations and dynamic structures, all in principle unpredictable from the standpoint of formal logic.
Furthermore, it has been empirically established that where the sub-systems have the capacity to replicate and mutate in some way (the normal condition of any significant "real" system), thus modifying the balance of the atomic relations, the system will in time either "die", or gravitate to a complex transition system, from a chaotic or structured state to a complex one, from a stable, predictable system to one giving rise to complex, "revolutionary" phenomena. Empirical computer simulation has reproduced analogues of systems (neurological or social) which learn, the origin of life from a "primeval soup", punctuated evolution, etc.
The scientists who are doing this work have expressed serious concerns about the state of the world economy, especially after the end of the relatively stable Cold War Period, and have tended to become fans of Heraclitus or Taoism; interestingly, none of them have so far recognised that a very precise science of the logic of complexity already exists in the Logic of Hegel.
As remarked above, formal logic reflects the relative stability in Nature. Formal logic works fine in physics, so long as atoms are hard little balls; but as soon as quantum behaviour slips into the picture and particles "leap", transform one into another, disappear and reappear, behave like waves and so on, formal logic gets into trouble.
But it should be noted, for very very much physics and chemistry even today, the "hard ball" model of the atom is quite sufficient for the purposes of practical and theoretical work.
In politics, the electoral system is the very embodiment of formal logic: 100,000 isolated human atoms utter "Yes" or "No" to a single question, and from this the most dramatic and usually desperately inadequate conclusions follow.